1. Field
One or more aspects of embodiments according to the present invention relate to frequency sources for use as local oscillators, and more particularly to a frequency-agile frequency source with good spurious performance.
2. Description of Related Art
Local oscillator (LO) system applications that require extremely fast frequency tuning capability (i.e., applications that require a frequency-agile frequency source) may use direct-synthesis based architectures. The output of such an architecture may be capable of tuning, i.e., changing frequency, faster than alternatives such as a phase-locked loop (PLL). Direct-synthesis architectures may also achieve better phase noise performance than a PLL-based counterpart. However, a direct digital synthesizer (DDS) may have relatively poor spurious performance. Thus, there is a need for a frequency agile frequency source architecture that provides acceptable spurious performance.